The change in the electronic character upon cisplatin binding to guanine nucleotide is transmitted to drive the conformation of the local sugar-phosphate backbone—a quantitative study
作者:Matjaž Polak、Janez Plavec、Anna Trifonova、Andras Földesi、Jyoti Chattopadhyaya
DOI:10.1039/a902330e
日期:——
conformation. The increase in the population of N-type conformers was rationalized with the strengthening of the anomeric effect in both 2′-deoxy and ribo nucleotides upon the formation of the Pt–N7 bond which promotes nO4′ → σ*C1′-N9 orbital interactions due to the reduction of π-electron density in the imidazole part of guanine. The additional stabilization of N-type conformers in Pt2+ complexes of ribonucleotides
本文已通过对Pt 2+络合2'-脱氧鸟苷3'的作用进行多核温度,pH *-和浓度依赖性NMR研究,评估了顺铂与DNA中鸟嘌呤N7结合的微观结构改变, 5'-双(磷酸氢二乙酯)1及其核糖类似物3,它们在分子内碱基间完全不存在相互作用的情况下,模仿了三磷酸二核苷中的中央核苷酸部分。所述Ñ 小号朝向pseudorotational平衡移Ñ型构象由17个21个百分点在298 K,分别,由此表明platination的自由能量传递到驱动糖构象。N人口的增加通过在Pt–N7键形成时增强2′-脱氧和核糖核苷酸的异头作用,使2型-顺式构象体合理化,这会由于π的减少而促进n O4' →σ* C1'-N9轨道相互作用-鸟嘌呤的咪唑部分的电子密度。的附加的稳定Ñ型中的Pt的构象异构2+核糖核苷酸的复合物是由于的调谐笨拙的[N9-C1'-C2'-O2']片段的效果,这是不存在于2'-脱氧核糖同行。N7的pla